5. Bulbophyllum yunnanense Rolfe, J. Linn. Soc., Bot. 36: 14. 1903.
蒙自石豆兰 meng zi shi dou lan
Bulbophyllum otoglossum Tuyama.
Rhizome 3.5-5 mm in diam., sections between pseudobulbs 1.5-3.5 cm, bract fibers hardly persistent. Pseudobulbs distant, prostrate on rhizome for ca. 2/3 of their length, ovoid, 2-4.5 × 1-1.4 cm. Petiole 0.2-4 cm; leaf blade elliptic(-ovate), 4-12 × 1.9-3.3 cm, acute. Inflorescence erect to spreading, 3.6-11 cm, 1-flowered or a raceme, 2-flowered; peduncle 0.8-4 cm; bracts ca. 3, longest 7-12 mm; rachis 0.3-1.5 cm; floral bracts usually tubular, 6-12 mm, acute, upper in a raceme sometimes elliptic, ca. 7 mm wide. Flowers resupinate, moderately opening, creamy yellow, densely spotted with red, lip yellow, spotted or suffused with red along sides, column yellow, face red. Pedicel and ovary 13-40 mm. Dorsal sepal recurved with top incurved, ovate, 9.5-12 × 6-9 mm, rather thick, glabrous, base rather broadly attached, margin entire, apex truncate to obtuse, apiculate; lateral sepals free, recurved, 10.5-15.5 × 7-11 mm, rounded to acute, otherwise as dorsal sepal. Petals recurved, elliptic, 7.5-11 × 4-7 mm, rather thin, glabrous, base broadly attached, margins ± entire to finely erose-denticulate, apex obtuse to acute; lip recurved, ovate, 6-10 × 3-5.5 mm (all without artificial spreading), thick; abaxially with a rounded median ridge over most of length of lip, surface glabrous; adaxially slightly concave proximally, convex distally, with a median slit over most of length of lip, proximally deepening and widening into a cavity bordered by 2 short, distally converging ridges, with 2 more ridges with wavy, proximally erose crests starting at lacerate part of margin and running almost parallel or converging slightly up to ca. 2/3 of length of lip, surface in between only slightly verrucose, surface toward margins coarsely and irregularly verrucose, margins deeply denticulate-lacerate at ca. 1/4 of length of lip, otherwise ± entire, apex obtuse. Column 3-4.5 mm, stigma inside with 3 keels, at its base without teeth, column foot without a tooth above ligament; stelidia triangular, ca. 1 mm, acute, with or without a small, deltoid, subacute tooth along upper margin, with an inconspicuous, widely deltoid, obtuse wing along lower margin, ca. halfway along column; anther abaxially ± glabrous and with high, narrowly conic, sharp crest; front margin not drawn out, slightly erose; pollinia with a small, thick stipe. Fl. Apr-Jun, Aug.
Epiphytic in (monsoon) forests, also lithophytic; 1400-2900 m. NW and SE Yunnan [Bhutan, Nepal].